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|
//! The timing rules of `peers.md` on whole nodes: joining and converging, dormancy and
//! return, and late messages that must not undo what newer ones said.
use std::time::Duration;
use serde_json::json;
use super::{Sim, has_neighbour, heads, peer, read, write};
use crate::document::replica::Epoch;
use crate::state::{AppState, Liveness};
use crate::swarm::bootstrap::Start;
use crate::transport::sim::LinkParams;
use crate::transport::{HeadsSummary, HelloRequest, Keepalive, ParsedMessage, RunId};
/// Long enough for anything that should happen within a few keepalives.
const SOON: Duration = Duration::from_secs(10);
#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
async fn three_nodes_join_and_converge() {
let sim = Sim::new(1);
let a = sim.start("a", &[], Start::Genesis);
let b = sim.start("b", &["a"], Start::Join);
let c = sim.start("c", &["a"], Start::Join);
let (a, b, c) = (&a, &b, &c);
sim.wait_ready(&[a, b, c], SOON).await;
let swarm = a.swarm_id().await;
assert!(swarm.is_some());
assert_eq!(b.swarm_id().await, swarm);
assert_eq!(c.swarm_id().await, swarm);
// A write anywhere reaches everyone.
write(b, "users/bob", json!({"name": "Bob"})).await;
sim.wait_until("c has b's write", SOON, move || async move {
read(c, "users/bob/name").await == Some(json!("Bob"))
})
.await;
// Concurrent writes merge to one document.
write(a, "users/alice", json!(1)).await;
write(c, "users/carol", json!(3)).await;
sim.wait_converged(&[a, b, c], SOON).await;
for node in [a, b, c] {
assert_eq!(read(node, "users/alice").await, Some(json!(1)));
assert_eq!(read(node, "users/carol").await, Some(json!(3)));
}
}
#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
async fn converges_with_duplicated_and_reordered_messages() {
let sim = Sim::new(2);
sim.net.set_default_link(LinkParams {
duplicate: 0.3,
delay: (Duration::from_millis(1), Duration::from_millis(40)),
..LinkParams::default()
});
let a = sim.start("a", &[], Start::Genesis);
let b = sim.start("b", &["a"], Start::Join);
let c = sim.start("c", &["a"], Start::Join);
let (a, b, c) = (&a, &b, &c);
sim.wait_ready(&[a, b, c], SOON).await;
for round in 0..10 {
write(a, &format!("a/{round}"), json!(round)).await;
write(b, &format!("b/{round}"), json!(round)).await;
write(c, &format!("c/{round}"), json!(round)).await;
}
sim.wait_converged(&[a, b, c], SOON).await;
for node in [a, b, c] {
for prefix in ["a", "b", "c"] {
assert_eq!(read(node, &format!("{prefix}/9")).await, Some(json!(9)));
}
}
assert!(sim.net.counts().duplicated > 0);
}
/// A peer that hears nothing for `dormant_after` is dormant; once messages flow again
/// it is active, re-handshakes, and syncs what it missed.
#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
async fn peer_goes_dormant_and_returns() {
let sim = Sim::new(3);
let a = sim.start("a", &[], Start::Genesis);
let b = sim.start("b", &["a"], Start::Join);
let (a, b) = (&a, &b);
sim.wait_ready(&[a, b], SOON).await;
// Only neighbours are judged, and a node joins the member list (which neighbours
// are computed from) within 5 s of becoming ready: until then the other doesn't
// count it as a neighbour.
sim.wait_until(
"a and b are each other's neighbours",
SOON,
move || async move { has_neighbour(a, "b") && has_neighbour(b, "a") },
)
.await;
sim.net.take_down("b");
sim.wait_until("a finds b dormant", SOON, move || is_dormant(a, "b"))
.await;
sim.wait_until("b finds a dormant", SOON, move || is_dormant(b, "a"))
.await;
let dormancies = peer(a, "b", |p| p.incidents.dormancies).await.unwrap();
assert!(dormancies >= 1);
// Written while apart.
write(a, "while/apart", json!(true)).await;
assert_ne!(heads(a).await, heads(b).await);
sim.net.bring_up("b");
sim.wait_until("a finds b active", SOON, move || async move {
!is_dormant(a, "b").await
})
.await;
sim.wait_until("b finds a active", SOON, move || async move {
!is_dormant(b, "a").await
})
.await;
sim.wait_until("b has what a wrote meanwhile", SOON, move || async move {
read(b, "while/apart").await == Some(json!(true))
})
.await;
sim.wait_converged(&[a, b], SOON).await;
}
async fn is_dormant(node: &AppState, other: &str) -> bool {
peer(node, other, |p| {
matches!(p.liveness, Liveness::Dormant { .. })
})
.await
== Some(true)
}
/// R17: a message sent before the peer's last epoch change and delivered late doesn't
/// flip the epoch we recorded for it back; a new run of the peer starts its count over.
/// The peer is a "ghost" whose messages are injected, so their order is the test's.
#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
async fn late_epoch_does_not_flip_a_peers_epoch() {
let sim = Sim::new(4);
let a = sim.start("a", &[], Start::Genesis);
sim.wait_ready(&[&a], SOON).await;
let swarm_id = a.swarm_id().await.unwrap();
let epoch = |generation: u64| Epoch {
generation,
id: [generation as u8; 32],
};
let hello = |run: RunId, epoch: Epoch, epoch_seq: u32| {
ParsedMessage::Hello(HelloRequest {
swarm_id: Some(swarm_id.clone()),
epoch,
epoch_seq,
auth: Vec::new(),
ready: true,
run_id: run,
})
};
let ping = |epoch: Epoch, epoch_seq: u32| {
ParsedMessage::Ping(Keepalive {
heads: HeadsSummary::of(Vec::new()),
epoch,
epoch_seq,
ready: true,
syncs_with_you: false,
})
};
let a = &a;
let recorded = move || async move {
peer(a, "ghost", |p| (p.epoch, p.epoch_seq))
.await
.expect("a knows the ghost")
};
let first_run: RunId = [1; 16];
sim.net
.inject("ghost", "a", &hello(first_run, Epoch::GENESIS, 0))
.await
.unwrap();
assert_eq!(recorded().await, (Some(Epoch::GENESIS), Some(0)));
// The ghost switched twice; we hear of the second switch first.
sim.net
.inject("ghost", "a", &ping(epoch(2), 2))
.await
.unwrap();
assert_eq!(recorded().await, (Some(epoch(2)), Some(2)));
// The PING from between the switches arrives late: ignored.
sim.net
.inject("ghost", "a", &ping(epoch(1), 1))
.await
.unwrap();
assert_eq!(recorded().await, (Some(epoch(2)), Some(2)));
// So is one from before both.
sim.net
.inject("ghost", "a", &ping(Epoch::GENESIS, 0))
.await
.unwrap();
assert_eq!(recorded().await, (Some(epoch(2)), Some(2)));
// The ghost restarted: its new run counts from 0 again.
let second_run: RunId = [2; 16];
sim.net
.inject("ghost", "a", &hello(second_run, epoch(2), 0))
.await
.unwrap();
assert_eq!(recorded().await, (Some(epoch(2)), Some(0)));
assert_eq!(
peer(a, "ghost", |p| p.run_id).await.unwrap(),
Some(second_run)
);
sim.net
.inject("ghost", "a", &ping(epoch(3), 1))
.await
.unwrap();
assert_eq!(recorded().await, (Some(epoch(3)), Some(1)));
// One ahead peer isn't enough for a ready node to rejoin.
assert_eq!(a.local_epoch(), Epoch::GENESIS);
assert!(a.is_ready().await);
}
|
